This invention relates generally to computer networks and particularly to networks with a relatively small number of nodes.
Computer networks connect computers and other devices together so that various computers on the network can share files, programs and resources. For example, it may be desirable to centralize files on one computer and allow access through the network from other computers. In addition, it may be desirable to share resources such as a printer with a number of computers. All of these functions can be achieved through computer networks. As a result of the advantages of computer networks, home computer networks are becoming more prevalent. Many homes have more than one computer and, for the reasons described above, many users would like to share resources and files among those computers.
Today, some builders provide houses which are pre-wired for such computer network connections. The homeowner merely plugs in the various components into pre-wired wall jacks. However, these pre-wired connections tend to be cost prohibitive for most homeowners.
Networks generally come in two basic types. The most common type uses twisted pair cables and includes what is known as a network hub. The hub includes a plurality of cable connectors so that each computer on the network may be connected to the hub. Some networks use coaxial cables where the cable goes directly from computer to computer without using a network hub.
The Ethernet is a standardized way of connecting computers into a network. The standards for the Ethernet are set forth in the Institute of Electrical and Electronics Engineers (New York, N.Y.) IEEE 802.3 standard. Most common Ethernet systems today transmit data at a rate of 10 million bits per second. A newer Ethernet version called Fast Ethernet has a bandwidth of 100 million bits per second and is sometimes referred to as 100BaseT. The 10 million bits per second networks are generally called 10BaseT when twisted pair cabling is utilized.
A popular network cable is unshielded twisted pair cable (UTP). Generally, UTP cable connects the Ethernet network by coupling the computers in a star arrangement. At the center of the star is the hub. UTP cable is generally connected to various devices such as computers through UTP connectors called RJ-45 connectors. The RJ-45 connectors are similar to the plug-in connectors used to connect telephones (which are called RJ-11 connectors).
There are a variety of rules for Ethernet connections compliant with the IEEE standard. One of the basic rules is that there may not be more than three hops. A hop is a connection from one device to another. In addition, there are rules with respect to the maximum length of cable. For 10BaseT cable, the maximum length is generally 100 meters. This normally means that about 90 meter runs may be used between nodes assuming 10 meter cables are used to connect a computer or other device to an RJ-45 connector.
While network technology has been applied widely to larger businesses, the cost has been prohibitive in many cases as applied to home and small business applications. A large component of the cost associated with home networks is the need to rewire existing homes to provide the Ethernet connections. Normally, this involves using UTP cabling and RJ-45 connectors to provide a plurality of connection points in different rooms of the house. These connection points are then wired together using the UTP cable to form the network. Usually, in a 10BaseT system, the network would also include a hub.
For existing homes, the wiring expense alone is prohibitive, and even for new homes, the expense is sufficiently great that new homes commonly do not include network wiring.
Thus, there is a continuing need for a network system that avoids the need for extensive rewiring or special network wiring.
In accordance with one aspect, a computer network includes a plurality of nodes. A programmable switching network allows the nodes to be connected in a plurality of different ways.
In accordance with another aspect, a computer network includes a plurality of nodes connected to telephone lines. Telephone wires connect the various nodes to one another. A high frequency power supply for the nodes is connected to those telephone wires. However, a filter is arranged to isolate the network power supply from the external telephone service.